Hamish: > > an idea: write a little script to make a vector coversheet index. > > maybe output that with the HTMLMAP driver for an interactive web > > browser pull up. > > > > I am not sure, but I think v.patch does not clean topology so > > overlap may be ok.
Ivan: > Wouldn't it be better to save non-overlapping parts and an > intersection as separate polygons? A separate attribute will be > needed to store the list of IDs of the covering images. see overlapping polygon example at: http://grass.ibiblio.org/screenshots/vector.php > > # store current region > > g.region save=old_region > > It makes me wonder each time I see such a fragile construct like > this, will GRASS ever support overriding the region > ``temporarily''? (E. g., via a command line argument, or an > environment variable.) there is, see GRASS_REGION and WIND_OVERRIDE shell variables: http://grass.ibiblio.org/grass63/manuals/html63_user/variables.html but saving & restoring g.region isn't need for this task, it is just being nice leaving the place as you found it. The script is not dependent on the starting region. And I fail to see how that's fragile? No more fragile than trusting anything else written to the disk. > > v.in.region out="${MAP}_box" > > Oh, perhaps `v.in.region' could be patched to print the category > of the vector feature it creates (if requested)? ie have a new cat= option added to set the cat number. (default "1") right now it always creates as cat 1. > I guess, this usage pattern is quite common for `v.in.region'? no idea. I've used the module a lot and this is first time I've had to worry about that. > And, could there be something a bit more clever than storing the > region of the image as a vector feature? the user can get as complicated as they like.. > A combination of downsampling, `r.mapcalc' (to obtain the fill mask), > and `r.contour', may be? r.contour is not so good for ortho photos or high resolution land use map with many small areas. But again, up to the user.... > > v.patch in=map_index_old,"${MAP}_box" out=map_index > > May there `v.patch -a' be used instead? Like: > > v.patch -a in="${MAP}_box" output=map_index yes, that's the correct way. Hamish ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
